Automatic Bell Siphon Explained

This is a demo of a bell siphon I built in collaboration with a couple of engineering professors. There are certain cases where it would be nice to be able to create a siphon without any intervention, a self-priming or automatic siphon: the next level of siphonry. It's built out of an acrylic sheet and a piece of clear pipe. Thanks to Rolf Hut and Pete Marchetto for inviting me to collaborate on their project.
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[@PracticalEngineeringChannel]

A lot of people have been commenting about the fluid tension theory of siphons. A siphon can indeed function without ambient air pressure in specific circumstances, but the bell siphon is relying on air pressure. More info in paragraph 5, here: en.wikipedia.org/wiki/Siphon#Theory

[@Mukeshmiktecrep]

According to me how siphon works: Once primed the weight of water going down in the pipe creates a suction in the pipe and pulls the liquid in the container above. You can sense that suction if you put your thumb on the pipe opening at the suction point.

[@mastertrey4683]

Mukesh right but since your thumb is not a the liquidn it can not get sucked in

[@ADogNamedStay]

MikTecRep how much pressure does the suction produce, and how high can it lift from the fulcrum?

[@runakovacs4759]

Which way does the Soxhlet extractor work?

[@twilightgardenspresentatio6384]

Practical Engineering thank you so much

[@Scruffy001]

there was a local news story here a long while ago about a group of teens siphoning gas from vehicles. They eventually hit an RV park and mouth siphoned a tank just not the fuel tank it was the septic holding tank.

[@musicalADD_theband]

🤮

[@alexandermcclure6185]

OOOOOH i bet they learned their lesson! (probably the wrong one though...)

[@pakistaniraveasylum1396]

That's a poopspiracy

[@direghostman]

Me: The pythagorean chalice is a cup that spills everywhere if you pour too much liquid in it. Smartass Friend: All cups do that

[@ferociousmaliciousghost]

This is why you give them the cup instead of telling them about the cup.

[@naveenkondeti5494]

all cups spill the additional liquid beyond the capacity of the cup but pythogorean cup spills out the complete liquid

[@AlphasysNl]

Very nice and clear explanation of the ancient device called the Pythagoras cup, also known as the greedy cup.

[@PunzL]

yes it is, a.k.a. greedy cup

[@kalebbruwer]

Because if you fill your cup properly you are apparently greedy.

[@ElectraFlarefire]

There are some great examples on Thingaverse if you want to print a Pythagoras cup too. Made some in PET-G for friends.

[@Djhg2000]

+Electra Flarefire Did you remember to cover the surfaces with food grade epoxy? If you didn't, small pockets of bactetia will form at the layer transitions. Obviously alcohol will kill off most of them but bare 3D prints are not to be considered food safe for this reason. There are probably other ways to make them safe for food but it's the only way I've heard of to pass actual food safety requirements. If nobody is trying to drink from them then that's fine too, however curiosity is very difficult to deal with sometimes. That said I love printing with PET-G, it's like it was made for printing.

[@ElectraFlarefire]

The cup was printed in PET-G, I normally print in ABS and acetone wash for smoothness(Do a lot of molding, made a number of silicon cups, the pythag cup was too complicated for this) but not in this case as I liked the translucent look. We flush it through with hot soapy water, rince then dry well. Plus it's only ever used with wine and water. Food grade regs are interesting. There are different ratings for contact(Biscuit cutters, even good 'ol budget brand ABS passes this one easily), holding(Glasses/plates) and storage(Containers). For example pewter(containg lead) is safe for the first two but never for storage.) If your layer adhesion is very good, they are typically about as safe as wood(Also porous) or things like a plastic chopping board that has been used biologically speaking so hot soapy water and let them dry completely before putting away normally works well. Spray down with dilute bleach if you want to be make sure. But to my knowledge very, very few 3d printers are certified for food grade for everything, even though you can get the filament.

[@Raymonddurann]

Working on my degree in hydroponic/aquaponics. Most ebb and flow systems have some type of bell syphon used. Up until now, I had never known how it works. Thank you sir for keeping me one step ahead👍

[@Firecul]

Nice to give Clive a shout out

[@dancoulson6579]

I agree. BigClive is one of my favorite subscriptions.

[@dancoulson6579]

Speaking of which, I've just subscribed to this channel too now!

[@kimvibk9242]

BigClive sent me here.

[@bdf2718]

Anyone who includes a clip of Clive must be worth watching.

[@stoatrepublic]

Big Clive is a legend and is always welcome in Norfolk...

[@ThisOldTony]

as always, great video. love the models & the graphics.

[@PracticalEngineeringChannel]

Thanks Old Tony!

[@petrolheartgarage1567]

Props to both of you, your channels are awesome!

[@yyabay]

Tony we look forward for new videos...I have a 250A inverter welder, Can you explain how to tig weld with an ordinary inverter welder with air cooled torch? Can you do that for me? I realy love your videos and watched them all several times. See ya.

[@adolfemmanuelesparas3922]

The Man himself, in the flesh!

[@koaasst]

when youtube was in its infancy i learned how to build a complete aquaponic system, and still have a box in the garage with the old pvc bell siphons. blast from the past!

[@DMahalko]

In many cases the siphon's purpose is an intermittent surging flow, as this saves water for cleaning/flushing purposes. But, if the input flow is too small, water can just dribble over the lip of the drain tube and it can't form a water seal. If the input flow is about the same as the outlet capacity, the siphon can enter an undesired steady state where it never stops flowing. More complex siphons use additional air communication tubes, air chambers, and U-traps, to assure the flow is reliably intermittent without entering a steady state.

[@drrwatcher]

Yes, and along with tube size scaling and flow rate, the whole system is also dependent on the surface tension, viscosity and density of the fluid. Thus making auto-siphons very finicky. Many people get caught scaling up models that don't adequately entrain the air in the top of the siphon, or the water in the bottom of the inverted siphon in the case of a geyser airlift pump.

[@thelongroad9750]

What if you want a steady state?

[@Hagledesperado]

If you want a steady state, there's no reason to use an auto siphon to begin with.

[@JamesCoyle95]

Have you considered making a clock that uses a series of siphons and chambers to represent time with water?

[@PracticalEngineeringChannel]

Cool idea!

[@JamesCoyle95]

Practical Engineering I've wanted to make one for a while but haven't had the time to work out the volume of all the chambers and it requires a bit of precision getting the siphon timings right.

[@PaprikaX33]

well in Europa Center in Berlin, there is a working water clock that spans from 1st floor to ground floor.

[@PaprikaX33]

and it seems really complicated

[@Nevir202]

Haha you haven't got the time, thus you don't have a clock so again you "haven't got the time." :-p

[@TheGhirlinzoni]

Hi! My name is Fernando and I'm from Brazil. I'm a Mechanical Technician here and I like your videos and explanations.

[@carlbussmann7559]

Another great self-explanatory and useful video by Grady. Also use flexible tubing immersed completely under the surface, block off the outflow end and release the blocked end into the lower container.

[@zacknicley8150]

“Automatic siphon” sounds like what they would call an electric water pump in the 1800s.

[@olivier2553]

bell spihon are used to release softener on washing machines

[@erg0centric]

Olivier Nicole that's what I was watching for, to learn more about my washing machine. I have cleaned many machines but never understood the process by which it worked.

[@josugambee3701]

Ahh... so THAT's how it works! I've always wondered how the liquid was able to get out of the little tray!

[@simontay4851]

Softener makes the dispencer drawer go mouldy

[@SimonGreensocialmarketing]

Olivier , i on't really doubt what you are saying here, but why are they using this method, surely simple over flow when water is added from above wold do the job anyway?

[@tookitogo]

Simon Green Without the siphon the softener tray would not empty at all. It would just stay full of water (with some residual softener). With the siphon only a small amount of residual water remains.

[@kurtisnimmert7555]

this is a concept that I have tried to explain many times to my less engineering interested friends, who are interested in hydroponics, in the past with no success. but this demonstration is simple and beautiful and with its help i am sure they will get it

[@looksintolasers]

SUGGESTION FOR FUTURE VIDEOS: I love this video because it has a nice, uncut 15 second section just showing the siphon doing its thing. It feels like being in a lab and just watching a demo! Many of the newer videos will show off The Device at the beginning but never give us just a straight section where we can watch how it works and observe. Please keep the little demo sections in the middle of the videos!

[@Vei2aC]

i have never seen a bell siphon before never even heard of one, love the simplisity of it and how it works so well, your model is a real nice way to show it working, this vid was sooo cool for me, thank you verry much =].

[@josebenitez3732]

Ashley Smith if you love this you'll love the Ram Pump. Loads of videos on KZbin. Enjoy.

[@Vei2aC]

i will go check that out my friend, i really enjoiy looking at stuff and how it works, and even reverse engineering it for a better understanding, thank you muchly =], knolage is priceless.

[@hellelujahh]

"The next level of siphonry"

[@RealLuckless]

I'm happy that I'm not the only one who rather enjoyed that line.

[@arvind.chhimpa]

Almost in every house there is flush tank

[@coreymcconnell1908]

I am looking at purchasing a home with a bell siphon septic, my research brought me here. This was all I needed to understand the basic principles, thank you.

[@Greenketch1]

Corey, Good on you for doing research on your new system. I work with Dosing siphon systems quite a bit. If you have further questions gimme a post or a shout.

[@isettech]

Larger systems may require additional engineering for septic. Large diameter pipe tends to act as a weir without starting a flushing cycle. For septic applications, look into piloted siphons. A small lower siphon is used to start a cycle. The upper bell of the small pilot siphon is plumbed to the larger siphon which has it's discharge submerged in a lower tank or barrel to prevent drawing in air. When the small siphon starts, it draws air from the bell of the large siphon and keeps drawing air as it's flow increases until it is able to flush out the remaining air into a full flush cycle. For even larger septic applications, the pilot is able to start several large siphons in parallel.

[@seth7745]

This is why I stopped using cylinder type airlocks for wine brewing. They are essentially bell siphons, but not intentionally by design. The idea is that you have the inner cap floating and water level bellow the top of the inner pipe so CO2 can escape while brewing without letting air back in. However, if for some reason the pressure reverses momentarily, it becomes and auto siphon and send the nasty water from the trap into your wine.

[@muh1h1]

really cool, love that you liked clive also! :)

[@LogicBob]

Great video Grady. I have known about the Pythagoras cup but I really enjoyed hearing about the practical applications of the concept. Thanks for sharing!

[@MeVsThevoices]

Logic Bob it's a Grady cup

[@LogicBob]

***** That's what I said. ;-)

[@pauljoyko5320]

One practical use of this siphon are bongs. In this case it's called a percolator. It's probably the most fun practical application of it^^

[@Mostlyharmless1985]

It’s weird, I remember watching this KZbin video several months ago. Then, a few weeks ago I was enginerding a stand pipe for my aquariums overflow, the design goal being to achieve laminar flow to reduce gurgling, but to not create a siphon. Without realizing what I was doing, I created a bell siphon. Then, I put a small hole in the top of the cap covering the bell to keep it from being a 100 % siphon. Then, to get super clever I set another hole in the stand pipe just above the main grill to account for blockages so it would become a siphon if the water level got too high. Where it is strange is I didn’t do any of this consciously, but with my understanding of how water in these situations behave, gained from watching this video. I *learned* something. On the internet. From a site that is “hmm, that’s interesting whelp on to watching cats try to fit themselves into ridiculous spaces!” “If you do things right, it won’t appear like you’ve done anything at all.”

[@clanravencub]

Just wanted to say how great your channel is and how much we love it. You explain things really well and in great detail. It's fantastic to have things explained properly and not dumbed down. This is how we can spread the love of engineering and the beauty of a well engineered and simple and elegant solution

[@brandonhall6084]

passive technology fascinates me.

[@solfeinberg437]

Right - it's intelligent design versus constant energy consumption and its concomitant costs (financial, environmental, materials, etc.).

[@hamsandwich780]

I remember being astonished by the Pythagoras cup as a kid, though they called it the greedy cup at the time.

[@zacharbison8763]

I've used this in my garden, 3 watt solar pump to fill the feed tank from the collection res (takes all day) and the bell siphon to flood the beds (~15 min). Beds drain to res and everything starts again when the sun comes back up. Works great as long as it stays clean. Great vid as always!

[@privateinformation9384]

I’m glad channels like this exist on KZbin. You actually learn something

[@fohdeesha]

+1000 points for repping big clive

[@Tomyb15]

But siphons work even in a vacuum. This has been tested with ionic fluids to prevent boiling due to the low pressures. Meaning pressure is only partly the reason for siphoning but it's mostly cohesion.

[@robertmolldius8643]

Yes, yes and yes.

[@oceanceaser44]

I homebrew beer and at the top of our carboy, we use an airlock which uses the same process but backward. As the air in the sealed container increases, it forces air up the tube and pushes the water out of the bell until the air makes contact with the outer atmosphere. It burps, equalizing the pressures outside and in and thus the atmospheric pressure pushes the water back into the airlock. Pretty cool!

[@EdwardConnors]

Very cool. I used to use this technique to drain the water bath into the sink at work. You can just submerge the whole tube in the reservoir to fill it up, then pull one end out. No suction required!

[@Mukeshmiktecrep]

According to me how siphon works: Once primed the weight of water going down in the pipe creates a suction in the pipe and pulls the liquid in the container above.

[@seth7745]

That is how it works. In a regular siphon, atmospheric pressure is irrelevant for such a short drop. It only comes into play for the auto siphon. The way he explained a regular siphon here was inaccurate because atmospheric pressure is also pushing the water back up from the bottom end, which cancels out the atmospheric pressure at the top. Fluid pressure differential from gravity is the only measurable factor neglecting pipe friction.

[@RetnuhN]

You should make a video explaining what happened at the Oroville dam and what they're doing to remediate the situation

[@verbotn]

Its been a while since I've seen one of these bell siphon tanks serving the urinals in a men's room. The high water consumption of them going through their flush cycles all day & night, even when the building might be closed is the reason we don't see many of them remaining. Constant water flow into the elevated porcelain tank, then that intermittent flushing noise when it drops through the piping header into a bank of urinals. I'm a plumber and they were old tech when I started in the trade over 30 years ago.

[@hj8607]

1:57 If you try this it won't actually work unless you put a check (back flow ) stop valve in the pond at the start of the intended siphon . (unless there is a very very long down flow tube on the lower run ). If you don't, the water you put into the hosing at the mid point will simply empty backwards into the pond as quickly as you try to load the pipe .

[@175griffin]

I watched a 3 and a half minute unskippable ad even though I have ad block. Does that qualify me as a patron?

[@erg0centric]

Griffin you were bring punished for having adblock installed

[@donperegrine922]

3 and a half minutes,UNSKIPPABLE? KZbin is a human rights violator! hahaha (Not as bad as twitter targeting certain users, but still bad)

[@tin2001]

Griffin Those seem to come up at times... Go back and open the video again and you should get a different ad, which is usually either shorter or skippable, or both.

[@ModMINI]

As a fellow KZbin content creator, I'll say do what you want, but we do care about the 0.001, which ads up with lots of views, and it helps to pay for our livelihood. It is very much appreciated if you watch the ads, and we might create less content if we get paid less for doing it....

[@hamsandwich780]

probably just get a better ad blocker - ublock origin works fine.

[@isaacray9405]

Isn't this essentially how a toilet works? When you flush, the upper bowl empties into the lower bowl raising the water level so the siphon can start which pulls the rest of the contents out? Please correct me if I'm wrong. ;) Also great video as always Grady! I'm always excited to see your videos in my feed. :D

[@PracticalEngineeringChannel]

Yes, I believe a toilet is another kind of self-priming siphon called a "U" siphon.

[@DeJayHank]

But first you must empty the lower bowel

[@DMahalko]

Old toilets used 8 gal / 30 L to fill the bowl, overtop the outlet pipe and start the siphon. Modern toilets use less water, by using a jet hole aiming into the output pipe, ramming water up the siphon over the bend to start it, using the height of the tank to pressurize the jet.

[@tookitogo]

Eden's Aquaponics Depends on the toilet design. Most American domestic toilets are siphons; most European ones are not..

[@vincentrobinette1507]

This exact principle is used in the detergent dispenser cup in my front loading cloths washer. For powder detergents, this bell siphon cup is removed, and the powder is poured straight into the trough. There is a minimum and maximum level. If you don't use enough, the shot of water from the valve block may not start the siphon. If too much detergent is added, it will immediately start the siphon process, and completely empty into the trough. it is triggered by a water solenoid, which over-fills it to start the process when queued by the timer circuit. you have to be careful when closing the drawer, to not accidentally start the siphon prematurely.

[@richdelgado3405]

These videos should be required viewing in high school. They are really interesting enough to maybe get a kid or two on the path to becoming an engineer.

[@alexh3601]

Practical Engineering.... Rube Goldberg machine.... I feel like there's a joke in there somewhere.

[@Maninawig]

If he made it into a cube, it could be called a Practical Rube X Cube

[@markholm7050]

Check out the chemical apparatus known as a Soxhlet extractor.

[@occamraiser]

clear and concise description of something that is obvious but I hadn't seen before - even though I have heard urinals automatically flushing, I'd always assumed it was some form of hinged (tipping) tank in the reservoir. Thanks for the illumination.

[@bosox2318]

Years ago I was in Australia and was fascinated with the urinal trough in a pub I visited in Sydney. The reservoir was above head level (>6') and there was a constant stream running into it slowly filling it up. Every three min or so the reservoir would empty automatically as a "flush" cycle to rinse the trough. This video made me realize I was probably looking at a bell siphon in action. And yes it was weird that a dude was standing in the bathroom for more than a few 3 min cycles just staring at the pissing trough plumbing.

[@jessicasanchez134]

¡Hey! I love your videos. Thanks for the inspiration. I'm watching you from Mexico. Next year I'll be entering the UNAM. Your videos make engineering so awesome.

[@CodytheDeer]

Hey, that's Pythagoras cup. I feel so smart when I get it

[@JoshSideris]

Wow. I used to do these engineering competitions in university. The vast majority of them involved moving or pumping water. We always found a way to do it and took a lot of wins, but this technique would have been the cherry on the cake if only I'd known about it.

[@adamh8908]

I've watched multiple videos on Bell Siphons and every time I learn something new. LOVE the video!!!!

[@PushingThroughThePain]

That is so freaking cool! I love learning about hydrodynamics. Thank you!

[@ShiroAndRin]

Wow! This is practically a capacitor for liquids.

[@stevedoe1630]

ShiroAndRin Great point. I always used to think of a hydraulic accumulator as a “liquid capacitor”. Both build up pressure (hydrostatic, or hydraulic), but this has an inherent automatic method for discharge of the prime.

[@ruben3305]

I remember when I was about 5yrs old, a person had ran out of fuel in the middle of nowhere. My father pulled over to help out. Luckily we had a hose and the man a couple of empty water jugs. He siphoned the fuel out of our vehicle and into the empty jugs then we siphoned the jugs into the mans cars. I will never forget how cool and neat little trick that was.

[@user-te7zz8mv3x]

thank you so much for the demo and diagrams! i tried watching several videos previously and didn’t understand why the bell siphon worked for aquaponic systems … now i get it. thanks again!

[@tommynorthwood]

I have a bong with two levels of water in it and that's how it works.

[@googleplusisdead]

Interesting, thanks. Can't think of a practical use for myself/homeowner, however.

[@jannegrey593]

It's used in toilets for example. At least some and in some parts of the world. That way once you flush water reaches only certain level (for example needed to clean the inside of the toilet) and then quickly is siphoned out of the drain. I know a lot of Eastern bloc countries had toilets like this. I think you will also see them in Netherlands etc. It is rare in English speaking world. Also flushing itself can use this, you just put a cap on the siphon - and when you press to flush it pulls the cap up allowing for water flow. Sometimes there are holes drilled that when 1 part of the "button" is pressed, you only drain half a tank.

[@Cloud7050]

3:25 cool how the air gets pulled downwards in a thin line till it reaches the bottom of the riser, then it's finally able to all get pushed out and the siphoning becomes very fast

[@bleedingpolarbear]

I dont usually comment but i swear your videos have me looking at common problems with an engineers mind. Whats affordable, effective, and consistent. Draining a swamp in my back yard with this.

[@BlameItOnGreg]

Ooh, you should do a video on ram pumps.

[@jstreutker]

Is there a video explaining the whole board?

[@PracticalEngineeringChannel]

It really is as simple as the diagram shows. Just imagine the black lines are 1" wide strips of clear acrylic.

[@PlasmaHH]

I think he means the complete goldberg installation

[@PracticalEngineeringChannel]

Oh! Sorry I misunderstood. Yes! Rolf pasted the link below and I have added it to the video description.

[@jstreutker]

Thanks, Grady. Dankjewel, Rolf. :-)

[@kogureee]

About 3 years ago, I accidentally made a siphon using two plastic cups of different heights and a bendy straw. I was so baffled about how it worked back then. I only found out the answer now. Thanks.

[@T42nk]

I adore your models! In physics classes we learn a lot of mathematical models to describe reality but your physical models take intuition to a whole another level. Please do more, like the ground water flow model, these help illustrate the principles we'd like to teach in experimental physics but are extremely abstract to a novice or extremely difficult to visualise.

[@jarlove]

but... will this work the same if the drain tube goes in a loop over an edge, to work as a normal siphon?? the drain pipe never goes above the "drain chamber" in the examples you show, so it makes me wounder..

[@PracticalEngineeringChannel]

No, sorry if that wasn't clear. This type of siphon can't prime itself to discharge water at a higher level than the peak water level in the reservoir.

[@jarlove]

that's what i suspected :)

[@croyce7699]

NorseMarauder Might it work if the volume in the reservoir is sufficient to fill the outlet hose over the crest, thus forming a 'regular' siphon?

[@daksh8747]

354k subs and 354k views Coincidence? I don't know

[@matambale]

1 year later, 1.1M subs, and 1.1M views.

[@EnhancedNightmare]

This effect is used in soxhlet apparatus in chemistry. The process of soxhlet extraction is truly mesmerising.

[@OfficialSamuelC]

This is how my washing machine (and many others) dispense fabric softener! (Maybe only UK/EU where we don’t have the same washing machines as those in the US). It’s fascinating watching the water fill up in the fabric softener compartment, and then when it gets to a certain level, it sucks it up through the tube in the middle!

[@Neilhoh3]

Off topic, but what is being used to glue the acrylic sheets together for the container & bell.

[@paweadamczyk4096]

I'd like to know that as well.

[@NoisyPlaces]

We used chloroform (carefuly) to join perspex in school.

[@raykent3211]

x x in case your still interested.... If you leave a scrap of clear polycarbonate in acetone with a lid on the jar to stop the acétone evaporating you end up with a goo that can be used for this. Not all plastics dissolve in acétone.

[@amarpreetmehta7]

thank you for explaining the science behind bell syphon as i am making a DIY aquaphonic system for myself, it was of great help as you showed the system with a transparent device

[@chickenofthecave1406]

Amazing video as always. It actually helped me out a lot because I have to drain the gasoline out of my lawn mower every year so that it doesn't freeze. But they way I'd do it was just to let it run and use up the gas. Now I can just use the syphon technique. Thank you so much!

[@richardzielenkievicz1914]

One of the best explanations of a bell siphon that I have ever seen!

[@cultuuedpetri]

thank you for not dubbing over the shots of you talking to the camera. I could actually watch this while video!

[@PracticalEngineeringChannel]

I've gotten this comment a few times. What do you mean by dubbing over? I sometimes use a separate microphone to capture audio, but I have never used audio that was recorded at some other time over a video.

[@cultuuedpetri]

Practical Engineering first off, if like to thank you for the knowledge you've been doling out. It's always nice to see videos that obtain more than titties and ass on the KZbins. In you're older videos, when you would cut to a shot of you speaking into the camera. The audio didn't seem like it was syncing up to your month perfectly. Like they were recorded separately. If you are getting that quality of audio with an open Mic in a room, you should let "Electroboom"(a fellow KZbinr) in on your secret. I heard him talking about this very problem...something about his auto gain doing weird things.

[@ThePizzaGoblin]

You can see the moment the vacuum gets pulled. An air bubble forms in the riser as the vacuum pulls the remaining air from the bell. So cool

[@krishankumarrai4450]

Your content is great sir. Highly effective for the upcoming civil engineer who lack technical knowledge due to poor financial conditions. You are doing a great job....👏👏👏

[@Majorvideonut2]

Just what I was looking for. My idea was to have a larger tube with a hose attached to a smaller tube that was short of the top of the larger tube and my siphon hose attached to the smaller tube. I figured if I put a floating ball in the larger tube it would float until the puddle of water that I was draining siphoned then the ball sealing off the siphon hose tube trapping water into the line until the next rain and starting the siphon automatically. This automatic bell siphon sounds even better.

[@Chris_In_Texas]

Same thing that is in my LG front loading washing machine. In the detergent, bleach and fabric softener cups. This will allow them to almost fully drain the cups during the cycle of any of the cups contents as well as any water used to start the flow. 👍👍

[@lifesgood6480]

That was the best bells syphon tutorial I've found yet, good job and thank you.

[@allenlin6880]

Center Enamel Bolted steel tanks have a large variety of system applications, mainly including fire protection water storage tank, potable water tank, anaerobic digester, biogas tank, dry bulk storage tank, leachate tank, municipal sewage tank.

[@the_real_hislordship]

My front loader washing machine has a bell siphon for the fabric softener dispenser. Put the softener in. When last cycle starts the valve for the water opens and fills that dispenser causing it to overflow. The siphon part is used when the water stops as it keeps going to make sure the dispenser is completely emptied.

[@nicmaz37]

I have 3 rain barrels that have 2 hoses autosiphon into each as the rain falls into 1 barrel from the gutter, the last barrel is very well filtered.

[@stumetcalfe3017]

Glad you engineers figured out how the urinals in every men's room worked for years before water conservation came into vogue.

[@rupe53]

A friend uses something similar to recycle grey water from showers to water his garden. He starts with a series of 55 gallon drums that cascade from one to the next (horizontal pipe on the sides) and that lets the water have time to settle out any solids. The last drum is on a siphon so when it is full the whole thing drains in one shot. Not perfect because sometimes the water flow is too slow and it just trickles over. If he catches it right he can use the bath tub drain to hold back a few gallons then let it go out more quickly to prime it up.

[@herrpez]

Dang, my boy Clive getting some love! Nice!

[@yootoob7048]

I love a Bell Siphon. To me it's one of those simple yet clever tools.

[@ai4px]

These are also used in pig parlors to suddenly make a lot of water flush off the pig waste from the floor. A large reservoir fills slowly for hours and finally surges and flushes.

[@raykent3211]

Here's a little tip for those wanting to make one. You may find that a slow feed results in water trickling down the outlet pipe without sealing over, no syphon action. But then a slightly greater input feed rate gives you a syphon action that drains the tank at a lower rate than you're putting water in, flush too slow. You may be suffering from stubby pipe syndrome. Speed up the flush by increasing the vertical distance between top and bottom of the outlet pipe.

[@buixote]

This will be a great addition to my rain barrel which currently requires priming at the beginning of the rainy season.

[@erikkayV]

Grady is the man. You make everything interesting.

[@karlslicher8520]

The magic of the fabric softener compartment.

[@Greenketch1]

Excellent video, It is great to see that you are bringing engineering tech to normal use. I do want to comment that you have made a small error. You are exactly correct in the operation of a Bell Siphon. They are used as a base for the siphons that are used in Septic systems. Technically septic systems would be termed as a dosing siphon. The difference is that dosing siphons include the trap (the P-trap style run below the bell) and an atmospheric vent internal to the tank. The fundamentals are very close to the same. The trap and vent only allow for a more predictable and adjustable dose control. This would be the vertical distance between the trigger point and the break point. This is only for the adjustment of drainfield dose volume.

[@FreestyleFlame]

I love siphons and i love aquaponics. I remember i was a kid I tried to build a perpetual motion device using siphons.

[@therandomman6647]

I LOVE your channel, I am using it to get refrenses for the sump I'm going to build for my fishtank

[@ryanksiazek]

Just an FYI: To siphon properly you should submerge enough of the line into the fluid, plug the end (use your thumb) pull it out enough to place it into the container you want to siphon to and unplug it (release your thumb). This way you will not suck with your mouth and probably get a taste of the gasoline or what ever else you are trying to siphon. In your pond drain graphic with the valves you could just lower a large hose into the water, plug the end with your hand, pull out enough to get the siphon going and release your hand.

[@isettech]

There is a way to scale this up to very large auto siphons as this does not work with pipe sizes such as 2 inch to 12 inch in diameter. Worked on one for a river rock digester for a septic system. Having small diameter pipe and low flow dribbling would not properly wash over the rocks in the digester. The solution was to install a set of 6 inch auto siphons in parallel with a 1 inch pilot auto siphon. The tops of all siphons were connected with 1/2 inch air pipe. The discharge of each siphon was in a barrel. The cycle started with the septic tank becoming full. The small auto siphon starts and lowers the upper pressure in each of the other siphons. Since air can't enter from above or below, this raises the water in the main siphons and as they start spilling and thus expel air, the set of all siphons start creating the unified flush cycle of the septic tank into the digester rock field. A small auto siphon is interesting to watch. A 20,000 gallon flush is really impressive. Septic system was installed for a wilderness resort facility which serviced the commercial kitchen, showers, restrooms, etc. The original engineer who designed the system did not install the pilot or air plumbing expecting all to operate at the same time. It would not. It would only dribble in low flow times and would occasionally flush one siphon under heavy load which did not properly coat the digesting bed of rocks. Sometimes the engineer will have the auto siphon but not enough knowledge of how to scale it to a larger project. I sometimes get called in on projects to fix engineering mistakes.

[@xqiuvmah]

My shower (which is the lowest point in my house) sometimes floods with sewer water when we get heavy storms. In order to prevent the sewer water from leaving the shower I use a 50ft. Garden hose to siphon out the water. I fill it from a faucet with one end blocked, then I disconnect the full hose and bring the open end to the shower and make sure it is completely submerged. Then all I need to do is unscrew the other end, which I run down hill out the window, and it starts siphoning and won't stop until the water level decreases

[@TurboPidgeon]

Great video, first time I saw a thing like this, its awesome, think i will use it in some of my projects.. Only one little thing that's wrongly explained in the video is the siphon works in a vacuum(assuming you use very low vapor pressure fluid like mercury or ionic fluids), so the atmospheric pressure isn't whats driving it, it is cohesion between water molecules.

[@PracticalEngineeringChannel]

+TurboPidgeon Fluid tension is not enough to explain the bell siphon because of the interaction with air in the bell. Ambient air pressure is indeed what's driving the siphonic action

[@scotthannan8669]

Practical Engineering I think an excellent follow-up video would be to put a bell siphon into a vacuum chamber. Or even various types of siphons or similar things.

[@timothyball3144]

I watched this video twice and have watched a few others and I'm pretty sure that I know have it figured out how it works. Now I need to figure out how I can put it to practical use.

[@obst3085]

Didn't see it so I'll say it: a Soxhlet extractor in chemistry works that way too, you heat your solvent, it condenses into the Soxhlet, the hot solvent extracts the stuff you want and at some point the solvent gets sucked back to the original flask, meaning you enrich the solvent in what you want, and in the end you can just distill off the solvent to isolate your product. Did that in lab as a demo for fat content in hazel nuts.

[@fourdegreesc]

If you want to prime a long line for a syphon, as for your pond example, no valves are needed. Just hook it to your water spigot and fill the column (host) with water. You can hold it on the spigot with your fingers making the seal. It's that easy.

[@NerveriosNZ]

also commonly found in condensate drains inside hydro units and gas boilers. awesome stuff

[@MM-fq9gi]

bell siphon: most commonly found in laundry machines, in the liquid softener dispenser of the sliding drawer where you also add detergent and bleach.

[@stevetran73]

i finally completely understand how siphon really work. thanks so much for the video.

[@jean-pierreenglish5043]

This is one of my favorite videos of yours. Keep up the great work.